Oil painting is the process of painting with pigments that are suspended in an oil medium, typically linseed oil. Many artists using oil paints will paint on a canvas in layers. In one technique, an artist may apply several layers of paint using a technique known as “fat over lean.” This means that each additional layer contains more oil (has more “fat”) than the previous layer. This promotes proper drying of the layers of paint. In some cases, the artist may want the paint layers to blend with each other, while in others blending is not desirable. In any event, typically some drying of a paint layer must occur before another layer may be applied. While the oil paints will dry by themselves in time, often it is desirable to use an agent to help speed the drying process to allow the artist to continue working on the painting or when the work is finished. A similar process may be used for oil pastels, also called wax oil crayons. Oil pastels are typically comprised of pigment mixed with an oil and a wax binder.